m29dw256g Numonyx, m29dw256g Datasheet - Page 44

• Manufacturer Part Number: m29dw256g
• Description: 256-mbit X16, Multiple Bank, Page, Dual Boot 3 V Supply Flash Memory
• Manufacturer: Numonyx

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If the password mode lock bit is programmed and the user attempts to read the password,
the device will output FFh onto the I/O data bus.
An Exit Protection Command Set command must be issued to return the device to read
mode.
Password Unlock command
The Password Unlock command is used to clear the NVPB lock bit allowing to modify the
NVPBs.
The Password Unlock command must be issued along with the correct password.
There must be a 1 μs delay between successive password unlock commands in order to
prevent hackers from cracking the password by trying all possible 64-bit combinations. If
this delay is not respected, the latest command will be ignored.
Approximately 1 μs is required for unlocking the device after the valid 64-bit password has
been provided.
Exit Protection Command Set command
The Exit Protection Command Set command is used to exit from the lock register, password
protection, non-volatile protection, volatile protection, and NVPB lock bit command set
mode. It returns the device to read mode.